Jack, I'll try and help on the Air to Air the air goes from the turbo at about 500 degrees through the cooler that is cooled by the outside air and then to the engine at around 200+ degrees. It just uses the air like a radiator only without water. On the aftercooler it uses water to cool the air after the turbo. Have you ever noticed when you are driving your rig how in the rain and at night how much more power you seem to have , cooler air makes more power clear as mud huh

For every pound of boost you create 12 degrees of heat over ambient temperature. Example 100 degree day 20 pounds boost ,you would have 340 degee going into intercooler. I can get my intake temp. to 40 degrees over ambient. Pat

I have a ummins ISC 8.3 with turbo and Charge air cooler, the air is drawn into the air cleaner, then to the turbo to be compressed, then thru the GAC (its mounted in FRONT of the radiator) then into the engine, works great .>>>Dan

To show how well air to air intercooling works, virtually every Diesel engine in vehicles now (and for many years past) is both turbocharged and air to air intercooled.

When I turbocharged my 8V-71N, I had a custom air to air intercooler made for infront of the radiator (helps I had about 8" to play with). Don Fairchild, who had been working on 2 stroke Detroits most of his life, did the work and was the first one he had done. It works so well, Don has done numerous additional ones for other busnuts.

Bottom line- Turbocharging and air to air intercooling a 2 stroke Detroit REALLY wakes them up. Going to Las Vegas from L.A., I pull the Cajon pass and Baker pass 10mph faster, and they are the only two hills I have to down shift on. All other hills the bus goes over without down shifting-compared to numerous slow downs and down shifts before the turbo. Good Luck, TomC

I curious now. I've got an 8V92 Turbo aftercooled engine. Can a charge air cooler be installed to this setup and would it do any good? Would it be better to remove the aftercooler portion and just run the engine with the air charge cooler setup? Should i just back away form the keyboard and go back to yard work? Thanks, Mike

Mike, that was a option for the 8v92T from the 80's really brings them to life with more power more torque and better fuel mileage. There are 2 of us I know of now doing that, I had to have the manufacture redo my air to air because of space and because I didn't want fans on mine. And yes you do need to remove the after cooler and install a air defector in place of the after cooler some don't add the defector but I am going to add it just like the book shows. Space for the air to air is a problem on older buses but the manufactures can work it out and give you enough air flow and if you don't mind fans they are easier to install. FWIW mine and JIm's air to air units were around 1000 bucks plus piping

The intercooler sits in front of the radiator and the heat is released into the air around the radiator fins, slightly increasing the air temp hitting the radiator.

The aftercooler sits under the blower or in the intake airstream after the turbo, (4 stroke), and uses coolant to transfer the heat from the intake airstream into the coolant.

When aftercoolers and intercoolers first hit the market, the mechanics used to tell me I didn't need one with straight pipes because I didn't have a heat build up as I had no back pressure on the exhaust. I never proved or disproved that, but I think there is some truth to it.

Aftercoolers are usually aluminum and rarely leak air. Air to air intercoolers are generally plastic and have a lifespan that sometimes requires replacement. The intercooler will also be a little more maintenance sensitive because you have to keep the clamps/pipes etc. tight or you will not have any boost when it gets back to the engine.

Both can give you some free horsepower and improved fuel mileage.

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Mike, everyone does it their way the aftercooler on the 2 strokes are not real efficient the one on a 8v92 is 4 inches wide , 12 inches long and 3 inches deep. You don't get much cooling from a cooler where it sits down in the block between 2 heads and are level were the combustion takes place and water is 180+ and that is a small area plus going through the blower and making more heat. Our air to air units are made from aluminum

The intercooler/CAC on my bus is metal, probably aluminum, and it is almost as big as the radiator. Mine is in front of the radiator and it is a factory install. It somehow had some holes in it when I got the bus and a local radiator shop patched it up.

I have had to remove the intercooler two or three times to work on the engine (mostly cooling stuff) and I can get the intercooler out in less than an hour by myself. The intercooler is designed to be easy to work on unlike other things like the radiator! (It took half a day or more to remove the radiator.)

Thanks everyone for the responses. Didn't mean to hyjack your thread Jack. But this has got me to thinking, and that in itself could be dangerous. Anyway, i always wondered just how efficent that aftercooler could possibly be, considering where it is located and it uses the engine water/cooling system. In normal conditions, the water/cooling system is usually running between 170-195 degrees. So wouldn't that be the coolest the air charge gets? Stealing thoughts from drag racing, and bear with me here, couldn't some form of cool can system be developed? Maybe using some form of refrigated air from a small airconditioner system to cool the intercooler? Just tosing out some thoughts. I really have a lot of room in the back of my Scenicrusier due to the original air compressor and associated equipment being long gone. Heck, with that much room i could really hillbilly up something fantastic.

Any HP gain from cooler air would probably be offset by the HP required to run the refrigeration. With drag racing, things have to run for maybe five minutes at a time. On a bus things have to be able to run for hours on end potentially.

An air to air intercooler would probably be easier than a cool can system.

Brian, what i was thinking is that some buses have some large generators that make a lot of unused electricity. Why not put that electricity to use to drive some small air conditioning unit or possibly for those who have large basement type of units, run a set of lines back to the engine bay and make up a cold box back there. Heck, i'm about 450 miles from my bus and am just daydreaming about all the wonderful contraptions i could build. But i do know that i need to get the turbo off my 8V92 and have it checked. I seem to remember there was some 'slop' in the bearings. Thanks, Mike

I guess it would work if you always run the generator when going down the road. Me personally I don't run the generator on the road unless I need air conditioning. Then, I already have an air to air intercooler that seems to work fine.

Brian, what i was thinking is that some buses have some large generators that make a lot of unused electricity.

Michael,

Actually not really. I know that ours (20KW), uses less fuel the less electricity you are using. So we don't want to burn maximum fuel all of the time. FWIW

I think that you are meaning that they are capable producing more electricity. I don't believe that generators "store" extra, meaning that they don't produce "extra." However you have a interesting idea.

If one can gain extra HP for the main engine by running the generator, it might be worth it for some.

Generators will put out a minimum amount of power which could be more than one is actually using, but most aren't going to run a generator unless they have significant load. The refrigeration required for this cool can is probably gpoing to take more than minimum power.

Michael, we have a 4106 that has a 3 KW oil cooled generator mounted on the engine. That's 4 hp required for that output before allowing for losses. It requires that we burn an extra 1/4 gallon of fuel per hour at full output.

If we are using full throttle to climb a mountain AND taking full output from the generator, it cuts the delivered power for climbing by something over 4 hp. That doesn't sound like much, but it comes right from the power delivered to the drivers, so it's noticeable.

Another item that's noticeable is the fan, if it's on an electric clutch. That's enough to cost a gear while climbing.

In modern cars, if you are using full throttle, the air conditioner is cut off immediately and stays off until you reduce the throttle opening. This is to improve performance and to reduce overheating.

There is no free power; you just don't notice that it's gone in some of these cases.

Micheal_e, you could star with a couple temperature sensors, one on each side of the charge air cooler, and take some idea of what is going on. a smaller project but will satisfy your curiuosity and not cost a lot.

Since you have a water to air cooler, you could seperate it into its own system (pump and radiator, fan, etc) and maybe do what you said. with your temperatures you can decide if it is worth your while or not.

How about a cool can set up (only larger) like we used to use on the derby cars for the "heater core" radiators and "transmission cooler coils" ?We used to take an old big ice chest and drill four holes in it 2-1/2" holes for the 3/8" copper tubing for the "tranny coolers", & 2-1 1/4" holes for the heater hoses then we'd hook several heater cores in series inside the ice chest along with a 25'-50' coil of copper tubing. (depending on the size of cooler and the amount of "spare" tubing we could scrounge!) Then we'd pack it with dry ice for the "race". When I first started doing this everyone thought I was NUTZ, but B4 long everyone wuz do'n it! I even by-passed the whole radiator one night after taking a nasty hit to it that ripped it in half! Still won 2 heats and the feature on those "auxiliary" radiators in the cooler! Just a thought! FWIW BK

Very interesting... how about a cross of ideas from Busted Knuckle & NewbeeMC9. Reroute the aftercooling lines to a ice box type of affair? Put the ice box somewhere near the side of the bus, use a NACA type of duct to cool the aftercooler during the cooler months and then have a small air conditioner cooler for the warmer months. Like i said earlier, my bus and all my manuals are 450 miles away and all i have here is my daydreams and a couple of pics on the computer. Does anyone have any pics of where the aftercooler lines come out of the engine, or know of a web link that might show this? Thanks,